Apparatus for hardening metal surfaces



June 24, 1930. SHORTER ET AL 1,768,159

APPARATUS FOR HARDENING METAL SURFACES Filed Dec. 21, 1927 10 Sheets-Sheet 1 ATTORNEYS.

Julie 24, 1930. SHORTER ETAL 1,768,159

APPARATUS FOR HARDENING METAL SURFACES Filed Dec. 21, 1927 10 Sheets- Sheet 2 INVENTORS. I

' ATTORNEYS.

June 24, 1930. A. E. SHORTER ETA!- APPARATUS FOR HARDENING METAL sURFAcBs' Filed Dec. 21, 1927 Jun 24, 193.0.- A. E. \SHOVRTER ET AL 1;768,155-" APPARATILJS FOR HARDENING METAL SURFACES Filed Dec. 21. 1927 l0 Sheets-Sheet 4 g g A'IIORNEYI.

June 24, 1930. SHO-RTER ET AL I 1,768,159

' APPARATUS FOR HARDENING METAL SURFACES Filed Dec. 21. 1927 10 Sheets-Sheet 5 L- BM I ATTORNEY.

June 24, 1930.

A. E. S HORTER FA APPARATUS FOR HARDENING METAL SURFACES 1o Sheets- Sheet 6 Filed Dec. 21, 1927 INVENTORS:

ATTORNEYS.

June 24, 1930' SHORTER ET AL 1,768,159

APPARATUS FOR HARDENING METAL SURFACES Filed Dec 21. 1927 10 Sheets-Sheet 7 INVETORS.

g E ATTORNEYS:

June 24, 1930. A. E. SHQRTEfi ET AL ,159

APPARATUS FOR HARDENING METAL SURFACES Filed Dec. 21. 1927 g lolsheets-sheet 8 5 I ZZQV/ a] B 28 o I Z4 o 1 I f I Z9 3/ 3/ 30 7 I ATTORNEYS.

June 24, 1930. SHQRTER ET AL 1,768,159

APPARATUS FOR HARDENING METAL SURFACES Filed Dec. 21, 1927 10 Sheets-Sheet 9 INVE TORS: m

w I a g I ATTORNEYS,

June 24, 1930.- A. E. SHORTER E AL 1,768,159

APPARATUS- FOR HARDENING METAL SURFACES Filed Dec. 21; 1927 10-Sheets-Sheet 10 Zia/6 NyTOR: 02 $1M,

3 ATTORNEYS Patented June 24, 1930 ALBERT anwann sno'a'rrm, or LONDON,

AND CYBIL LE'Zlll. IBOUCHER, OF LITTLE BOO KEANE, ENGLAND, ASSIGNOBSTO THE P TENT GEAR HARDENING COMPANY,

LTII, OF LONDON, ENGLAND, A. BRITISH C ORATION APPARATUS Eli OR HABDENING MEJKAL SURFACES Application filed December 21, 1927, Serial 1T0. 241,682, and in Great Britain-"September 29, 1927' This invention relates to the art of hardening the wearing surfaces of gear teeth, but

wherein the metal to be hardened is locally heated to the requisite high temperature by suitiable high-temperature heating means, such as an oxy-acetylene flame,-which is traversed slowly along the surface to be hardened,the intensely heated surface being then immediately quenched, as by directing.,thereon a jet of cold water. In the aforesaid apparatus, an oxy-acetyleneblowpipe and a nozzle, or nozzles, (hereinafter referred to as the quenching nozzle) through which the quenching water is directed onto the heated surface are adjustably mounted on a reciprocable carrier which traverses the blow pipe tip and quenching nozzle accurately over the teeth ofa gear wheel under treatment. The carrier is traversed in a path parallel to the axis of the ear wheel, back and forth across the face 0 said wheel, and means are provided for automatically re- 7 versing the movement of the carrier so as to harden the face of one tooth during the forward movement and the face of a succeeding tooth on the return movement. The

arrangement is such that the uppermost face tank'in which the gear wheel to be treated is rotatably supported. The heating flame directed upon the tooth locally disperses the liquid film over the tooth and heats a portion only of the tooth at a time, the remainder ofthe tooth and part of the gear wheel being kept cool by the liquid.- As the flame 1s tra versed along the tooth the successive portions Y of the latter are heated to the re uired-degree and then immediately coole by a j t.

of cold liquid directed thereon.

' t For practical purposes, it "is more desirvable 'tq'apply the heating flame while theblowpipe is movin across the face of the gear in only'one' 'rection, so as to avoid treatment;

Figs. 11 and -12 illustratethe support and I "emng worm wheels; and

the complication of reversing the angular position of the blowpipe. One of the ob- ]ectsofthe present invention is therefore to economize gas during the reverse movement of the blowpipe in a machine arranged to apply the heat only during the forward movement of the blowpipe. This is ac comphshed b mechanism which automatically shuts 0 both the-oxygen and fuel gas at the end of the forward movement of the blowpipe. 1

7. Other objects'of this inventon are to prov1de means for automatically turning the gear or other article to be surface hardened to present successive teeth in proper positlon to be operated on by the heating and quenching devices; more completely cooling the parts of the artlcle sub ected to the high-temperature heat so as to further minimize liability of distor tlon;

to provide an improved support that to provide means for is adjustable to take work of varying shapes,

the same; Fig. a view, partly diagrammatic, illustizating theuse of additional cooling jets to prevent distortion;

Figs Sand 10 are detail views of the improved. gear support, .the first adjusted to carry a spur gear and the second to carry a double spiral or herringbone gear for associated appliances adjusted to treat bevel gears- I Figsi 13, 14 and 15 illustrate'the of tlns invention employed in surf rinciples ace hard- Figs. 16 and 17 illustrate the principles of parts heng shown in section Figs. 3, 4, 5, 6'and 7 are detail views of this invention applied to the surface hardening of worms.

inclusive, being here employed for surface hardening the'teeth of a spur gear G which may be rotatably mounted to be turned step- "by-stepfor presenting successive teeth to a high-temperature heating device, such as a blowpipe B adapted to produce an intense flame, an oxy-acetylene blowpipe being adyantag'eous for this purpose.

The suporting means for the gear to be treated is disposed in a suitable water tank ,T which may be provided with an overflow weir 20 adjustable by means of a hand wheel 21 to vary the water level in the tank, as

, indicated in Figs. 6 and 7 Suitable means may be "provided for supplying and distributing water to the several parts of the appa-, ratus, and as shown a water pipe 22 is secured to and extends along three sides of the inside wall of the tank. This pipe is ;provided with .an inlet 22 andat various points with plugged outlets 22", any one of .which may be opened to couple a hose connection thereto.-

. The improved work support constitutes an important feature of the present machine since it is designed to be adjusted to rotat ably support various types of gears so that their teeth may bepresented successively to 'the heating blowpipe and quenching jet. As here shown, the improved support consists of a .pair of standards rising from a .base 24' which is turnable along suitable] bearing surf-aces concentric with the turn-.

table 25 at the bottom of the tank. The base 24 may be secured in any one of its various tapered heads adapted to be tightened in a correspondingly tapered groove 25 of the turntable 25, as more clearly shown in Fig.

9. The standards are 'made of two telescopically adjustable sections, upper ends of the lower sections 23 being provided with central ,socket's 23'- to receive the threaded stems of ,yokes 26 which are vertically adjustable by means of'the nuts 26' hearing against the upper ends of the lower sections. The gear G or any other type of gear, as will be hereinafter explained, is rotatably supported by the pair of yokes 26. The upper end of each yoke carries a rockable trunnion 27 to -ro-' tatably support an end of the threaded gearcarrying shaft 28. At one end the shaft 28 has a collar 28' and a'nut 28" which-are disposed on opposite sides of one of thetrunnions 27 to prevent endwise movement of the shaft 28. A pair of clamp plates 29 are adjustable'toward each other by nuts 29' in the shaft 28 to grip a gear between them.

(I he plates 29 desirably have opposed conical faces-29 adapted tofit into the hub opening of a gear. These conical faces may thus ,ciated quenching means. The heat blowpipe and rotary adjustments by bolts 24' which havebe accommodated to gears of different sizes and securely clamp the gear in position.

and the gear thereon in any desired angular.

position. This support is therefore universally applicable for mounting spur gears as well as beveled gears, herringbone gears, and

other types of work in proper position to present their teeth or other parts to the high temperature heating means and its asso- P for delivering a quenching jet of cold water or other suitable liquid immediately behind the blowpipe are mounted on a slide 30 that is vertically adjustable as-by a handle 30 and an associated screw, along suitable ways .on the front end of a slide 31 which is hbri zontally adjustable by a handle 31 and associated gear 31 The slide 31 is adjustable along suitable ways on a carriage 32, to move the blowpipetoward or away from the work. Further adjustment of the blowpipe may be obtained by pivoting it, as at 302 on a bracket. 301 of the slide 30, raising or. lowering the free end by an adjusting screw 303, and securing it in any adjusted position by a wing nut- 304 on the blowpipe which engages a slotted arm, 305. on the bracket 301. The carriage 32 is propelled by a lead screw S along suitable ways on a frame 33. parallel to the tooth or other surface to be treated. It will thus be seen that the blowpipe and its associated quenching jet may be adjusted verti-- cally and horizontally in various directions to set these devices in proper position to treat gears of any diameter or to treat other surfaces of varying shapes.

v The lead screw S is rotatably mounted in the frame 33 and may be driven at different speeds by a motor M which may be connected through a .worm gear 33, a friction gear 3 1, a shaft 35 and worm gearing 36 to. the lead screw S. By manipulating the.

disc" 34! of the friction gearing 34 an infinite number of speed changes may be obtained and the lead screw S may be driven in-either direction. As shown in Fig. 4 and I its associated pipe I may be a projection on the lever 38' which is pivoted on the carriage at '38 and is normally held in an elevated position by a sprmg 40 connected to its free end and to the carriage 32, so that normally the connecting nut 37 is. disengaged from the lead screw S In order to set the nut 37 in engagement Wlthe the lead screw, the free endof the 1 largement 42" is designed to receive the lever is depressed b pushing downa handle width except at its upper end where it is formed'with'an enlargement 42". The enenlarged end 43', of a. releasing rod 43 which is slidable in opposite side walls of the carriage 32, the enlargement 43, being held in the recess 42' by a spring 43" that bears against a collar 44 on the rod 43 and against theside of the carriage 32.

The distance that the carriage 32 travels along the screw S may be limited b an abutment screw 45 which is carried by a bracket 45 adjustable to various positions alon the frame 33 lengthwise of the screw S. he adjustable abutment screw 45 is disposed in line with the rod 43 to be engaged by the collar 44 on the later wlien the carriage 32 has reached the limit of its movement in one direction. This engage-- 'ment depresses the rod 43 against the spring 43 and moves the enlargement 43' out of the recess 42-", whereupon the tension of the spring '40 acts to lift the lever 38- and disengages the nut 37 from the lead screw S stopping thetravel of the carriage, 32. It

. ment of the blowpipe B may be manually ingdownwardly on a knob K secured to the will thus be seen that the length of travel of the blowpipe B and its associated quenching jet along .the surface to be treated may be predetermined and the blowpipe-travel maybe stopped at any desired point by setting the abutment screw' as desired. Moreover the carriage 32 and the -movestopped at any point in their travel by 'pullouter end of the control rod 43. After the carriage 32 has reached .the limit ofits movement-in one direction and the nut 37 is disengaged, the carriage may be returned, to its initial position manually as by a handle J, n or automatically, and again set in motion to repeat its operation by depressing the handle' 41. A suitable weight D suspended over a pulley D and connected by a 'chain D" to the carriage 32'may be employed to automatically-return the carriage.

. to its initial position against the stop 33" when the nut 37 is released by the control .rod 43; l

When the carria e 32 reaches the end of its movement and .t e blowpipe has finished hardening one tooth or a 'v'en zone on a surface to be treated, it is esirable to autoits initial position to perform a succeedingoperation. The oxy en and the acetylene or other fuel gas may and 49, respectively to flexible hose connections 48 and 49', respectively, which lead to the blowpipe B. The supply of acetylene or gas mixture to a pilot-light B is not disturbed. The supply of oxygen and acetylene to the pipes 48 and 49 may be derived fromsuitable cylinders of compressed gases, and.

may be controlled by a p u valve V which operates in a valve casing V The outer end of the stem of the valve V carries a handle H by means of which the valve may be manually turned to admit to the pipes 48 and 49. As so adjusted, the valve V may be held in e supplied by pipes 48 I open'position by a latch L which has a catch to engage a right angle extension 50 rigidly connected tothe valve-plug V, aspring'L' being provided to hold the latch in this po sition. The latch L is pivoted at 51 on the carriage 32 and has a depending arm 52 arranged t% trip pawl 3 which may be adjustably secured to a bar on the frame 33 at any point lengthwise of the lead screw S. A torsion spring 54 surrounds the stem of the valve V and normally tends to close this valve which is, during the operation of the blowpipe, held open by the latch L. However, the trip 53 is so adjusted that it will engage the debe engaged by a spring-pressedpending arm 52 and disengage the latch-L from the projection 50 at the limit of'the' operating movement of the blowpipe, whereupon thetorsion spring 54 rotatesthe valve V to shut off both the oxygen and the 'acety- "lene. A manually operable lever 55, having .a button 55' connected to its free end, is connected by a link 55" to the latch arm 52 so that the gas maybe manually shut oil? when "ever desired, by depressing the button 55.-

Means may be provided toturn the gear -sufliciently aiter each tooth-hardening operation to bring the next tooth in position to be hardened. For this purpose indexing means or step-by-step mechanism may be employed. As illustrative of such mechanism, a pawl may be provided at the outer end of a rod- 61 which is secured by an adjusting screw 61' to a block 62 pivoted at 62 in the forked upper end of a lever F pivoted at F on'the rear end of the tank-T.. The depending end F of this levcr is provided with a curved slot 63 whereby a rod 64 carrying a pin 64' may be adjustably secured to the arm F at any point in the slot 63 at a variable distance from the pivoted F. This connection permits a variable movement for the her of teeth on the gear wheel that is being treated. The pawl'60 has inclined faces so that it may be withdrawn from the space between any tooth without exerting a return movement on the gear, and the forward movement of the pawl 60 is limited by an awl 60, depending upon the diameter of or t e numadjustable set screiv 60' mounted in a bracket on the tank T. The feeding movement of the pawl 60 is applied by the rod 64 which extends lengthwise of the machine and has its free end 64:" disposed in the path of a cam 65 mounted on and adjustable lengthwise of an operating rod 65' that is fixed to the carriage 32. Accordingly, with the cam 65 properly adjusted, when the carriage 32 reaches the end of its movement, the cam 65 engages the end of the rod 64 which actuates the lever F to push the pawl 60 forwardly to index or turn the gear sufliciently to set the succeding tooth in position with its-top sur-- faces to be hardened the ma or portion of above the blowpipe.

the gear or the surface is immersed in the water in the tank T, thus reducing the possibility of distortion and localizing the heat. In order to eliminate possibility of distorting the portion of the article above the water level, it

is desirable to apply cooling means to the article above the surface bein treated. As best shown in Figs. 2 and 8, ets of cooling liquid, such as cold water or water atomized by compressed gases, 68 and 69 across the face of the gear just The cooling nozzles are adjustably mounted on brackets 68 and 69 and receive water from suitable outlets 22, and desirably direct their jets from opposite sides of the ear through the channels and along sur aces between the teeth just above the one being treated. Heat conducted upwardly'into the article is thus carried away by these cooling jets and distortion from this source is minimized.

While Figs. v1 to 9 inclusive illustrate the invention .as applied to the surface hardening of spur gear teeth, it will be understood that the machine herein ,shown is equally well adapted tobe used for surface hardening the teeth of other'types of gears and similar articles. F or example, Fig. 10 diagrammatically illustrates the machine arrangedto harden the surfaces of one set of teeth of the herringbone gear Gh. ,Here

one of the yokes 26 is raised and the otherlowered to set the gear so that the teeth of one-half of its face will be parallel to the water-level in the tank T. Should any adjustment of the water level be necessary this may be accomplished byI ralsmg or lowering the weir 20. With the gear in further localize the heat and are directed by nozzles.

'indicated the blowpipe is'secure position as indicated in Fig. 10, the blowpipe B and its associated quenching jet pipe P may at or just below the water level to treat thistooth in the same" manner as in the case of spur ear teeth. Part of the gear above the tooth being treated may be cooled as already set forth, bydischarging one or more jets of cooling fluid through the channels and along the surfaces between the teeth.

The earindexing device 60, the automatic gas ut ofl mechanism, and other features of the machine shown in Figs. 1 to 9 are similarly applicable to the mechanism shown in Fig. 10.

be traversed lengthwise of the tooth Figs. 11 and 12 illustrate the machine adjusted so as to be capable. of surface hardening the teeth of bevel gears or similar articles. porting base 24 is turned about the vertical axis of the turntable 25 and secured in such a position that the teeth of the gear Gb will be presented to the blowpipe B in. a flame coinciding with the water level. The blowe B and its associated quenching I pipe the successive teeth of the bevthen traverse eled gear as each is automatically moved into operating position. Otherwise the mechanism .and operation for hardening bevel gear teeth and similar surfaces as the same as already described.

Figs. 13,14 and 15 illustrate a slight modification in the machine to adapt it for sur- To accomplish this, the sup- 7 face'hardening curved teeth such as those of the worm wheel gear Gw. After the worm wheel has been properly mounted between the clamp plates 29 of a support in all respects similar to the one shown in Fig. 9, the teeth at the water level are traversed by a blowpipe and its associated quenching Ion jet to successively harden them and the wheel is advanced tooth-by-tooth asa'lready described. In order to givethe necessary motion to the blowpipe and quenching means, a follower wheel 70 is mounted on a depending lever' 71 which has anarm 72 that supports the blowpipe and the pipe P. 'As

72 by pivot 73 and a slotted extension '74 which receives a pin 74 securing the blowpipe to the arm in any position to which it is adjusted by the thumb screw 75. The blowpipe supporting lever v71 is carried by the vertical slide 30 and a spring 76 presses the arm 71 toward the gear to hold the roller 70- against the periphery ofa guiding tooth on the gear wheel Gw. Accordingly,

when the carriage 32 moves transversely of the face of the gear, the roller 70'will engage and be guided by the tooth and. guide the blowpipe correspondingly along the face of the tooth being treated. Otherwise the mechanism and arrangement for surface hardening this gear wheel is the same as that already described.

to the arm- In Figs. 16 and 17 the invention is shown as applied to the surface hardenin of worms and similar spiral metal sur aces. The worm X maybe supported by the turntable and standards, as already described, but in the present instance the worm is continuously rotated to present successive portions of the tooth face to the blowpipe and l/Vhilethe wormis being rotated, the blowpipe flame and quenching jet are applied to the tooth face to harden the latter, and suitable jets of cooling fluid are discharged through the channels'fand' along surfaces on opposite sides of the surface and under Cir treatment to confine the heat and minimize distortion. The major portion of the worm is desirably submerged in the water in the tank T, leaving only a small section ofthe worm exposed.

It will be obvious that the improvedmachine maybe -modified so as to treat both faces of, the teeth of a gear'in one setting. For example, a carriage and its associated mechanism similar to that shown at the left end of the tank T in Fig. 1 may be provided at the opposite end ofthe tank, so that one face of each tooth will be treated by a blowpipe and its associated quenching jet oper- A teeth, comprisihg a blowpi immediately after intensely heating ating across one side of the ear, and the other face of each tooth will e treated by a similarly arranged blowpipe andits uenchin 'et operating across the opposite q g] Thus the teeth of the' face of" the girl v gear may be 'shed on both faces without removing it from the machine. With'this double arrangement, only a single indexing mechanism is employed, which may be'similar to-that herein. disclosed but mounted on the side instead 'of the end of the tank. Numerous other details of the herein-disclosed machine may be changed without departing from the principles of the invention andtherefore the invention is not intende J to be limited to the exact and described.

What is claimed is:

1. A machine for surface hardemng' gear for applying intense heat to a tooth, mea fortraversin'g said blowpipe relativelyto said tooth, means whereby the-tooth is progressively quenchezl 1 1 construction shown I means operative to automatically turn the sent a succeeding tooth for treatment, and

gear after a tooth has been treated to premeans operative to shut off the gas supply for the heating flame of said blowpipe after each tooth has been treated.

2. Ainachine for surface hardening a gear teeth; comprising a dewheel having vice for applying intense heat to a tooth; means for progressively quenching each tooth immediately after intensely heating it ;"a water tank in which said wheel ispartially submerged with the tooth undergoing treatment disposed substantially at the plying cooling medium to said wheel above the tooth being treated, such cooling medium applying means comprising a jet of 0001- ing ffuid flowing lengthwise of an adjoining tooth above the water level.

3. A machine for surface hardening a Wheel having gear teeth; comprising a device for applying intense heat to a tooth;

means for progressively quenching each tooth immediately after-intensely heating it; a'water tank in which said wheel is. par

tially submerged with the tooth undergoing treatment disposed" substantially at the waterlevel in said tank; and means for applying cooling medium tosaid wheel above the tooth being treated, such cooling medium being discharged lengthwise of channels between teeth of said gear ab'ovethe water level. v

4. A machine for surface hardening metals comprising a-support .for the article to be treated, such support having vertically adjustable standards and horizontally adjustable article clamping means carried by said standards.

'5. A machine according to claim 4, wherein said support also comprises meanswhereby said article may to the horizontal.

.- 6 A machine for surface hardening metals comprising a support for the article to be treated, such support being turnable about a vertical axis and having means supporting said article for rotation about an be mounted at an angle I axis disposed at an angle to said vertical axis. 7. A machine according to claim 4, wherein saidsupport is turnable about a vertical 3X18. I

8. A'machine for surface hardening gears comprising a water tank, a turntable thereon and adjustable ab ut the vertical axis of said turntable, a 1'0 atable gear support in, vertically adjustagcle standards mounted I 9. A 'machine according to claim 8, in

combination with means operative. toautomatically shut off the. gas'supply for the 75 water level in said tank; and means for apheating flame of said blowpipe after each tooth is treated.

10. A machine according to claim 8, in combination .wlth mechanism automatically operative to present the gear teeth in succession to said blowpipe and quenching means.

11. A machine for surface hardening articles comprising means forapplying intense heat to the surface of an article and immediately quenching such intensely heated surface; means for traversing the aforesaid means along the surface to be treated; means for automatically interrupting the movement of such aforesaid means; means operative to automatically interrupt the application of heat when. said moveinent is interrupted-and means for automatically returning such aforesaid means to its initial position while said heat is interrupted.

12. A machine for surface hardening gear teeth, comprising a blowpipe-for applying intense heat to a tooth, means for transversing said hlowpipe relatively to said tooth, means operative to shut ofl the gas supply for the heating fiame of said blowplpe, at a predetermined point in such movement, means whereby the tooth is progressively quenched immediately after heating it and means operative to automatically turn the gear after the tooth has been treated to present a succeeding tooth for treatment.

In testimony whereof we afiix our signatures.

ALBERT EDWARD SHORTER. CYRIL LETT BOUCHER. 

